-
Notifications
You must be signed in to change notification settings - Fork 53.3k
/
53c7xx.scr
1591 lines (1472 loc) · 45.9 KB
/
53c7xx.scr
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
#undef DEBUG
#undef EVENTS
#undef NO_SELECTION_TIMEOUT
#define BIG_ENDIAN
; 53c710 driver. Modified from Drew Eckhardts driver
; for 53c810 by Richard Hirst [richard@sleepie.demon.co.uk]
;
; I have left the script for the 53c8xx family in here, as it is likely
; to be useful to see what I changed when bug hunting.
; NCR 53c810 driver, main script
; Sponsored by
; iX Multiuser Multitasking Magazine
; hm@ix.de
;
; Copyright 1993, 1994, 1995 Drew Eckhardt
; Visionary Computing
; (Unix and Linux consulting and custom programming)
; drew@PoohSticks.ORG
; +1 (303) 786-7975
;
; TolerANT and SCSI SCRIPTS are registered trademarks of NCR Corporation.
;
; PRE-ALPHA
;
; For more information, please consult
;
; NCR 53C810
; PCI-SCSI I/O Processor
; Data Manual
;
; NCR 53C710
; SCSI I/O Processor
; Programmers Guide
;
; NCR Microelectronics
; 1635 Aeroplaza Drive
; Colorado Springs, CO 80916
; 1+ (719) 578-3400
;
; Toll free literature number
; +1 (800) 334-5454
;
; IMPORTANT : This code is self modifying due to the limitations of
; the NCR53c7,8xx series chips. Persons debugging this code with
; the remote debugger should take this into account, and NOT set
; breakpoints in modified instructions.
;
; Design:
; The NCR53c7,8xx family of SCSI chips are busmasters with an onboard
; microcontroller using a simple instruction set.
;
; So, to minimize the effects of interrupt latency, and to maximize
; throughput, this driver offloads the practical maximum amount
; of processing to the SCSI chip while still maintaining a common
; structure.
;
; Where tradeoffs were needed between efficiency on the older
; chips and the newer NCR53c800 series, the NCR53c800 series
; was chosen.
;
; While the NCR53c700 and NCR53c700-66 lacked the facilities to fully
; automate SCSI transfers without host processor intervention, this
; isn't the case with the NCR53c710 and newer chips which allow
;
; - reads and writes to the internal registers from within the SCSI
; scripts, allowing the SCSI SCRIPTS(tm) code to save processor
; state so that multiple threads of execution are possible, and also
; provide an ALU for loop control, etc.
;
; - table indirect addressing for some instructions. This allows
; pointers to be located relative to the DSA ((Data Structure
; Address) register.
;
; These features make it possible to implement a mailbox style interface,
; where the same piece of code is run to handle I/O for multiple threads
; at once minimizing our need to relocate code. Since the NCR53c700/
; NCR53c800 series have a unique combination of features, making a
; a standard ingoing/outgoing mailbox system, costly, I've modified it.
;
; - Mailboxes are a mixture of code and data. This lets us greatly
; simplify the NCR53c810 code and do things that would otherwise
; not be possible.
;
; The saved data pointer is now implemented as follows :
;
; Control flow has been architected such that if control reaches
; munge_save_data_pointer, on a restore pointers message or
; reconnection, a jump to the address formerly in the TEMP register
; will allow the SCSI command to resume execution.
;
;
; Note : the DSA structures must be aligned on 32 bit boundaries,
; since the source and destination of MOVE MEMORY instructions
; must share the same alignment and this is the alignment of the
; NCR registers.
;
; For some systems (MVME166, for example) dmode is always the same, so don't
; waste time writing it
#if 1
#define DMODE_MEMORY_TO_NCR
#define DMODE_MEMORY_TO_MEMORY
#define DMODE_NCR_TO_MEMORY
#else
#define DMODE_MEMORY_TO_NCR MOVE dmode_memory_to_ncr TO DMODE
#define DMODE_MEMORY_TO_MEMORY MOVE dmode_memory_to_memory TO DMODE
#define DMODE_NCR_TO_MEMORY MOVE dmode_ncr_to_memory TO DMODE
#endif
ABSOLUTE dsa_temp_lun = 0 ; Patch to lun for current dsa
ABSOLUTE dsa_temp_next = 0 ; Patch to dsa next for current dsa
ABSOLUTE dsa_temp_addr_next = 0 ; Patch to address of dsa next address
; for current dsa
ABSOLUTE dsa_temp_sync = 0 ; Patch to address of per-target
; sync routine
ABSOLUTE dsa_sscf_710 = 0 ; Patch to address of per-target
; sscf value (53c710)
ABSOLUTE dsa_temp_target = 0 ; Patch to id for current dsa
ABSOLUTE dsa_temp_addr_saved_pointer = 0; Patch to address of per-command
; saved data pointer
ABSOLUTE dsa_temp_addr_residual = 0 ; Patch to address of per-command
; current residual code
ABSOLUTE dsa_temp_addr_saved_residual = 0; Patch to address of per-command
; saved residual code
ABSOLUTE dsa_temp_addr_new_value = 0 ; Address of value for JUMP operand
ABSOLUTE dsa_temp_addr_array_value = 0 ; Address to copy to
ABSOLUTE dsa_temp_addr_dsa_value = 0 ; Address of this DSA value
;
; Once a device has initiated reselection, we need to compare it
; against the singly linked list of commands which have disconnected
; and are pending reselection. These commands are maintained in
; an unordered singly linked list of DSA structures, through the
; DSA pointers at their 'centers' headed by the reconnect_dsa_head
; pointer.
;
; To avoid complications in removing commands from the list,
; I minimize the amount of expensive (at eight operations per
; addition @ 500-600ns each) pointer operations which must
; be done in the NCR driver by precomputing them on the
; host processor during dsa structure generation.
;
; The fixed-up per DSA code knows how to recognize the nexus
; associated with the corresponding SCSI command, and modifies
; the source and destination pointers for the MOVE MEMORY
; instruction which is executed when reselected_ok is called
; to remove the command from the list. Similarly, DSA is
; loaded with the address of the next DSA structure and
; reselected_check_next is called if a failure occurs.
;
; Perhaps more concisely, the net effect of the mess is
;
; for (dsa = reconnect_dsa_head, dest = &reconnect_dsa_head,
; src = NULL; dsa; dest = &dsa->next, dsa = dsa->next) {
; src = &dsa->next;
; if (target_id == dsa->id && target_lun == dsa->lun) {
; *dest = *src;
; break;
; }
; }
;
; if (!dsa)
; error (int_err_unexpected_reselect);
; else
; longjmp (dsa->jump_resume, 0);
;
;
#if (CHIP != 700) && (CHIP != 70066)
; Define DSA structure used for mailboxes
ENTRY dsa_code_template
dsa_code_template:
ENTRY dsa_code_begin
dsa_code_begin:
; RGH: Don't care about TEMP and DSA here
DMODE_MEMORY_TO_NCR
MOVE MEMORY 4, dsa_temp_addr_dsa_value, addr_scratch
DMODE_MEMORY_TO_MEMORY
#if (CHIP == 710)
MOVE MEMORY 4, addr_scratch, saved_dsa
; We are about to go and select the device, so must set SSCF bits
MOVE MEMORY 4, dsa_sscf_710, addr_scratch
#ifdef BIG_ENDIAN
MOVE SCRATCH3 TO SFBR
#else
MOVE SCRATCH0 TO SFBR
#endif
MOVE SFBR TO SBCL
MOVE MEMORY 4, saved_dsa, addr_dsa
#else
CALL scratch_to_dsa
#endif
CALL select
; Handle the phase mismatch which may have resulted from the
; MOVE FROM dsa_msgout if we returned here. The CLEAR ATN
; may or may not be necessary, and we should update script_asm.pl
; to handle multiple pieces.
CLEAR ATN
CLEAR ACK
; Replace second operand with address of JUMP instruction dest operand
; in schedule table for this DSA. Becomes dsa_jump_dest in 53c7,8xx.c.
ENTRY dsa_code_fix_jump
dsa_code_fix_jump:
MOVE MEMORY 4, NOP_insn, 0
JUMP select_done
; wrong_dsa loads the DSA register with the value of the dsa_next
; field.
;
wrong_dsa:
#if (CHIP == 710)
; NOTE DSA is corrupt when we arrive here!
#endif
; Patch the MOVE MEMORY INSTRUCTION such that
; the destination address is the address of the OLD
; next pointer.
;
MOVE MEMORY 4, dsa_temp_addr_next, reselected_ok_patch + 8
DMODE_MEMORY_TO_NCR
;
; Move the _contents_ of the next pointer into the DSA register as
; the next I_T_L or I_T_L_Q tupple to check against the established
; nexus.
;
MOVE MEMORY 4, dsa_temp_next, addr_scratch
DMODE_MEMORY_TO_MEMORY
#if (CHIP == 710)
MOVE MEMORY 4, addr_scratch, saved_dsa
MOVE MEMORY 4, saved_dsa, addr_dsa
#else
CALL scratch_to_dsa
#endif
JUMP reselected_check_next
ABSOLUTE dsa_save_data_pointer = 0
ENTRY dsa_code_save_data_pointer
dsa_code_save_data_pointer:
#if (CHIP == 710)
; When we get here, TEMP has been saved in jump_temp+4, DSA is corrupt
; We MUST return with DSA correct
MOVE MEMORY 4, jump_temp+4, dsa_temp_addr_saved_pointer
; HARD CODED : 24 bytes needs to agree with 53c7,8xx.h
MOVE MEMORY 24, dsa_temp_addr_residual, dsa_temp_addr_saved_residual
CLEAR ACK
#ifdef DEBUG
INT int_debug_saved
#endif
MOVE MEMORY 4, saved_dsa, addr_dsa
JUMP jump_temp
#else
DMODE_NCR_TO_MEMORY
MOVE MEMORY 4, addr_temp, dsa_temp_addr_saved_pointer
DMODE_MEMORY_TO_MEMORY
; HARD CODED : 24 bytes needs to agree with 53c7,8xx.h
MOVE MEMORY 24, dsa_temp_addr_residual, dsa_temp_addr_saved_residual
CLEAR ACK
#ifdef DEBUG
INT int_debug_saved
#endif
RETURN
#endif
ABSOLUTE dsa_restore_pointers = 0
ENTRY dsa_code_restore_pointers
dsa_code_restore_pointers:
#if (CHIP == 710)
; TEMP and DSA are corrupt when we get here, but who cares!
MOVE MEMORY 4, dsa_temp_addr_saved_pointer, jump_temp + 4
; HARD CODED : 24 bytes needs to agree with 53c7,8xx.h
MOVE MEMORY 24, dsa_temp_addr_saved_residual, dsa_temp_addr_residual
CLEAR ACK
; Restore DSA, note we don't care about TEMP
MOVE MEMORY 4, saved_dsa, addr_dsa
#ifdef DEBUG
INT int_debug_restored
#endif
JUMP jump_temp
#else
DMODE_MEMORY_TO_NCR
MOVE MEMORY 4, dsa_temp_addr_saved_pointer, addr_temp
DMODE_MEMORY_TO_MEMORY
; HARD CODED : 24 bytes needs to agree with 53c7,8xx.h
MOVE MEMORY 24, dsa_temp_addr_saved_residual, dsa_temp_addr_residual
CLEAR ACK
#ifdef DEBUG
INT int_debug_restored
#endif
RETURN
#endif
ABSOLUTE dsa_check_reselect = 0
; dsa_check_reselect determines whether or not the current target and
; lun match the current DSA
ENTRY dsa_code_check_reselect
dsa_code_check_reselect:
#if (CHIP == 710)
/* Arrives here with DSA correct */
/* Assumes we are always ID 7 */
MOVE LCRC TO SFBR ; LCRC has our ID and his ID bits set
JUMP REL (wrong_dsa), IF NOT dsa_temp_target, AND MASK 0x80
#else
MOVE SSID TO SFBR ; SSID contains 3 bit target ID
; FIXME : we need to accommodate bit fielded and binary here for '7xx/'8xx chips
JUMP REL (wrong_dsa), IF NOT dsa_temp_target, AND MASK 0xf8
#endif
;
; Hack - move to scratch first, since SFBR is not writeable
; via the CPU and hence a MOVE MEMORY instruction.
;
DMODE_MEMORY_TO_NCR
MOVE MEMORY 1, reselected_identify, addr_scratch
DMODE_MEMORY_TO_MEMORY
#ifdef BIG_ENDIAN
; BIG ENDIAN ON MVME16x
MOVE SCRATCH3 TO SFBR
#else
MOVE SCRATCH0 TO SFBR
#endif
; FIXME : we need to accommodate bit fielded and binary here for '7xx/'8xx chips
; Are you sure about that? richard@sleepie.demon.co.uk
JUMP REL (wrong_dsa), IF NOT dsa_temp_lun, AND MASK 0xf8
; Patch the MOVE MEMORY INSTRUCTION such that
; the source address is the address of this dsa's
; next pointer.
MOVE MEMORY 4, dsa_temp_addr_next, reselected_ok_patch + 4
CALL reselected_ok
#if (CHIP == 710)
; Restore DSA following memory moves in reselected_ok
; dsa_temp_sync doesn't really care about DSA, but it has an
; optional debug INT so a valid DSA is a good idea.
MOVE MEMORY 4, saved_dsa, addr_dsa
#endif
CALL dsa_temp_sync
; Release ACK on the IDENTIFY message _after_ we've set the synchronous
; transfer parameters!
CLEAR ACK
; Implicitly restore pointers on reselection, so a RETURN
; will transfer control back to the right spot.
CALL REL (dsa_code_restore_pointers)
RETURN
ENTRY dsa_zero
dsa_zero:
ENTRY dsa_code_template_end
dsa_code_template_end:
; Perform sanity check for dsa_fields_start == dsa_code_template_end -
; dsa_zero, puke.
ABSOLUTE dsa_fields_start = 0 ; Sanity marker
; pad 48 bytes (fix this RSN)
ABSOLUTE dsa_next = 48 ; len 4 Next DSA
; del 4 Previous DSA address
ABSOLUTE dsa_cmnd = 56 ; len 4 Scsi_Cmnd * for this thread.
ABSOLUTE dsa_select = 60 ; len 4 Device ID, Period, Offset for
; table indirect select
ABSOLUTE dsa_msgout = 64 ; len 8 table indirect move parameter for
; select message
ABSOLUTE dsa_cmdout = 72 ; len 8 table indirect move parameter for
; command
ABSOLUTE dsa_dataout = 80 ; len 4 code pointer for dataout
ABSOLUTE dsa_datain = 84 ; len 4 code pointer for datain
ABSOLUTE dsa_msgin = 88 ; len 8 table indirect move for msgin
ABSOLUTE dsa_status = 96 ; len 8 table indirect move for status byte
ABSOLUTE dsa_msgout_other = 104 ; len 8 table indirect for normal message out
; (Synchronous transfer negotiation, etc).
ABSOLUTE dsa_end = 112
ABSOLUTE schedule = 0 ; Array of JUMP dsa_begin or JUMP (next),
; terminated by a call to JUMP wait_reselect
; Linked lists of DSA structures
ABSOLUTE reconnect_dsa_head = 0 ; Link list of DSAs which can reconnect
ABSOLUTE addr_reconnect_dsa_head = 0 ; Address of variable containing
; address of reconnect_dsa_head
; These select the source and destination of a MOVE MEMORY instruction
ABSOLUTE dmode_memory_to_memory = 0x0
ABSOLUTE dmode_memory_to_ncr = 0x0
ABSOLUTE dmode_ncr_to_memory = 0x0
ABSOLUTE addr_scratch = 0x0
ABSOLUTE addr_temp = 0x0
#if (CHIP == 710)
ABSOLUTE saved_dsa = 0x0
ABSOLUTE emulfly = 0x0
ABSOLUTE addr_dsa = 0x0
#endif
#endif /* CHIP != 700 && CHIP != 70066 */
; Interrupts -
; MSB indicates type
; 0 handle error condition
; 1 handle message
; 2 handle normal condition
; 3 debugging interrupt
; 4 testing interrupt
; Next byte indicates specific error
; XXX not yet implemented, I'm not sure if I want to -
; Next byte indicates the routine the error occurred in
; The LSB indicates the specific place the error occurred
ABSOLUTE int_err_unexpected_phase = 0x00000000 ; Unexpected phase encountered
ABSOLUTE int_err_selected = 0x00010000 ; SELECTED (nee RESELECTED)
ABSOLUTE int_err_unexpected_reselect = 0x00020000
ABSOLUTE int_err_check_condition = 0x00030000
ABSOLUTE int_err_no_phase = 0x00040000
ABSOLUTE int_msg_wdtr = 0x01000000 ; WDTR message received
ABSOLUTE int_msg_sdtr = 0x01010000 ; SDTR received
ABSOLUTE int_msg_1 = 0x01020000 ; single byte special message
; received
ABSOLUTE int_norm_select_complete = 0x02000000 ; Select complete, reprogram
; registers.
ABSOLUTE int_norm_reselect_complete = 0x02010000 ; Nexus established
ABSOLUTE int_norm_command_complete = 0x02020000 ; Command complete
ABSOLUTE int_norm_disconnected = 0x02030000 ; Disconnected
ABSOLUTE int_norm_aborted =0x02040000 ; Aborted *dsa
ABSOLUTE int_norm_reset = 0x02050000 ; Generated BUS reset.
ABSOLUTE int_norm_emulateintfly = 0x02060000 ; 53C710 Emulated intfly
ABSOLUTE int_debug_break = 0x03000000 ; Break point
#ifdef DEBUG
ABSOLUTE int_debug_scheduled = 0x03010000 ; new I/O scheduled
ABSOLUTE int_debug_idle = 0x03020000 ; scheduler is idle
ABSOLUTE int_debug_dsa_loaded = 0x03030000 ; dsa reloaded
ABSOLUTE int_debug_reselected = 0x03040000 ; NCR reselected
ABSOLUTE int_debug_head = 0x03050000 ; issue head overwritten
ABSOLUTE int_debug_disconnected = 0x03060000 ; disconnected
ABSOLUTE int_debug_disconnect_msg = 0x03070000 ; got message to disconnect
ABSOLUTE int_debug_dsa_schedule = 0x03080000 ; in dsa_schedule
ABSOLUTE int_debug_reselect_check = 0x03090000 ; Check for reselection of DSA
ABSOLUTE int_debug_reselected_ok = 0x030a0000 ; Reselection accepted
#endif
ABSOLUTE int_debug_panic = 0x030b0000 ; Panic driver
#ifdef DEBUG
ABSOLUTE int_debug_saved = 0x030c0000 ; save/restore pointers
ABSOLUTE int_debug_restored = 0x030d0000
ABSOLUTE int_debug_sync = 0x030e0000 ; Sanity check synchronous
; parameters.
ABSOLUTE int_debug_datain = 0x030f0000 ; going into data in phase
; now.
ABSOLUTE int_debug_check_dsa = 0x03100000 ; Sanity check DSA against
; SDID.
#endif
ABSOLUTE int_test_1 = 0x04000000 ; Test 1 complete
ABSOLUTE int_test_2 = 0x04010000 ; Test 2 complete
ABSOLUTE int_test_3 = 0x04020000 ; Test 3 complete
; These should start with 0x05000000, with low bits incrementing for
; each one.
#ifdef EVENTS
ABSOLUTE int_EVENT_SELECT = 0
ABSOLUTE int_EVENT_DISCONNECT = 0
ABSOLUTE int_EVENT_RESELECT = 0
ABSOLUTE int_EVENT_COMPLETE = 0
ABSOLUTE int_EVENT_IDLE = 0
ABSOLUTE int_EVENT_SELECT_FAILED = 0
ABSOLUTE int_EVENT_BEFORE_SELECT = 0
ABSOLUTE int_EVENT_RESELECT_FAILED = 0
#endif
ABSOLUTE NCR53c7xx_msg_abort = 0 ; Pointer to abort message
ABSOLUTE NCR53c7xx_msg_reject = 0 ; Pointer to reject message
ABSOLUTE NCR53c7xx_zero = 0 ; long with zero in it, use for source
ABSOLUTE NCR53c7xx_sink = 0 ; long to dump worthless data in
ABSOLUTE NOP_insn = 0 ; NOP instruction
; Pointer to message, potentially multi-byte
ABSOLUTE msg_buf = 0
; Pointer to holding area for reselection information
ABSOLUTE reselected_identify = 0
ABSOLUTE reselected_tag = 0
; Request sense command pointer, it's a 6 byte command, should
; be constant for all commands since we always want 16 bytes of
; sense and we don't need to change any fields as we did under
; SCSI-I when we actually cared about the LUN field.
;EXTERNAL NCR53c7xx_sense ; Request sense command
#if (CHIP != 700) && (CHIP != 70066)
; dsa_schedule
; PURPOSE : after a DISCONNECT message has been received, and pointers
; saved, insert the current DSA structure at the head of the
; disconnected queue and fall through to the scheduler.
;
; CALLS : OK
;
; INPUTS : dsa - current DSA structure, reconnect_dsa_head - list
; of disconnected commands
;
; MODIFIES : SCRATCH, reconnect_dsa_head
;
; EXITS : always passes control to schedule
ENTRY dsa_schedule
dsa_schedule:
#ifdef DEBUG
INT int_debug_dsa_schedule
#endif
;
; Calculate the address of the next pointer within the DSA
; structure of the command that is currently disconnecting
;
#if (CHIP == 710)
; Read what should be the current DSA from memory - actual DSA
; register is probably corrupt
MOVE MEMORY 4, saved_dsa, addr_scratch
#else
CALL dsa_to_scratch
#endif
MOVE SCRATCH0 + dsa_next TO SCRATCH0
MOVE SCRATCH1 + 0 TO SCRATCH1 WITH CARRY
MOVE SCRATCH2 + 0 TO SCRATCH2 WITH CARRY
MOVE SCRATCH3 + 0 TO SCRATCH3 WITH CARRY
; Point the next field of this DSA structure at the current disconnected
; list
DMODE_NCR_TO_MEMORY
MOVE MEMORY 4, addr_scratch, dsa_schedule_insert + 8
DMODE_MEMORY_TO_MEMORY
dsa_schedule_insert:
MOVE MEMORY 4, reconnect_dsa_head, 0
; And update the head pointer.
#if (CHIP == 710)
; Read what should be the current DSA from memory - actual DSA
; register is probably corrupt
MOVE MEMORY 4, saved_dsa, addr_scratch
#else
CALL dsa_to_scratch
#endif
DMODE_NCR_TO_MEMORY
MOVE MEMORY 4, addr_scratch, reconnect_dsa_head
DMODE_MEMORY_TO_MEMORY
/* Temporarily, see what happens. */
#ifndef ORIGINAL
#if (CHIP != 710)
MOVE SCNTL2 & 0x7f TO SCNTL2
#endif
CLEAR ACK
#endif
#if (CHIP == 710)
; Time to correct DSA following memory move
MOVE MEMORY 4, saved_dsa, addr_dsa
#endif
WAIT DISCONNECT
#ifdef EVENTS
INT int_EVENT_DISCONNECT;
#endif
#ifdef DEBUG
INT int_debug_disconnected
#endif
JUMP schedule
#endif
;
; select
;
; PURPOSE : establish a nexus for the SCSI command referenced by DSA.
; On success, the current DSA structure is removed from the issue
; queue. Usually, this is entered as a fall-through from schedule,
; although the contingent allegiance handling code will write
; the select entry address to the DSP to restart a command as a
; REQUEST SENSE. A message is sent (usually IDENTIFY, although
; additional SDTR or WDTR messages may be sent). COMMAND OUT
; is handled.
;
; INPUTS : DSA - SCSI command, issue_dsa_head
;
; CALLS : NOT OK
;
; MODIFIES : SCRATCH, issue_dsa_head
;
; EXITS : on reselection or selection, go to select_failed
; otherwise, RETURN so control is passed back to
; dsa_begin.
;
ENTRY select
select:
#ifdef EVENTS
INT int_EVENT_BEFORE_SELECT
#endif
#ifdef DEBUG
INT int_debug_scheduled
#endif
CLEAR TARGET
; XXX
;
; In effect, SELECTION operations are backgrounded, with execution
; continuing until code which waits for REQ or a fatal interrupt is
; encountered.
;
; So, for more performance, we could overlap the code which removes
; the command from the NCRs issue queue with the selection, but
; at this point I don't want to deal with the error recovery.
;
#if (CHIP != 700) && (CHIP != 70066)
#if (CHIP == 710)
; Enable selection timer
#ifdef NO_SELECTION_TIMEOUT
MOVE CTEST7 & 0xff TO CTEST7
#else
MOVE CTEST7 & 0xef TO CTEST7
#endif
#endif
SELECT ATN FROM dsa_select, select_failed
JUMP select_msgout, WHEN MSG_OUT
ENTRY select_msgout
select_msgout:
#if (CHIP == 710)
; Disable selection timer
MOVE CTEST7 | 0x10 TO CTEST7
#endif
MOVE FROM dsa_msgout, WHEN MSG_OUT
#else
ENTRY select_msgout
SELECT ATN 0, select_failed
select_msgout:
MOVE 0, 0, WHEN MSGOUT
#endif
#ifdef EVENTS
INT int_EVENT_SELECT
#endif
RETURN
;
; select_done
;
; PURPOSE: continue on to normal data transfer; called as the exit
; point from dsa_begin.
;
; INPUTS: dsa
;
; CALLS: OK
;
;
select_done:
#if (CHIP == 710)
; NOTE DSA is corrupt when we arrive here!
MOVE MEMORY 4, saved_dsa, addr_dsa
#endif
#ifdef DEBUG
ENTRY select_check_dsa
select_check_dsa:
INT int_debug_check_dsa
#endif
; After a successful selection, we should get either a CMD phase or
; some transfer request negotiation message.
JUMP cmdout, WHEN CMD
INT int_err_unexpected_phase, WHEN NOT MSG_IN
select_msg_in:
CALL msg_in, WHEN MSG_IN
JUMP select_msg_in, WHEN MSG_IN
cmdout:
INT int_err_unexpected_phase, WHEN NOT CMD
#if (CHIP == 700)
INT int_norm_selected
#endif
ENTRY cmdout_cmdout
cmdout_cmdout:
#if (CHIP != 700) && (CHIP != 70066)
MOVE FROM dsa_cmdout, WHEN CMD
#else
MOVE 0, 0, WHEN CMD
#endif /* (CHIP != 700) && (CHIP != 70066) */
;
; data_transfer
; other_out
; other_in
; other_transfer
;
; PURPOSE : handle the main data transfer for a SCSI command in
; several parts. In the first part, data_transfer, DATA_IN
; and DATA_OUT phases are allowed, with the user provided
; code (usually dynamically generated based on the scatter/gather
; list associated with a SCSI command) called to handle these
; phases.
;
; After control has passed to one of the user provided
; DATA_IN or DATA_OUT routines, back calls are made to
; other_transfer_in or other_transfer_out to handle non-DATA IN
; and DATA OUT phases respectively, with the state of the active
; data pointer being preserved in TEMP.
;
; On completion, the user code passes control to other_transfer
; which causes DATA_IN and DATA_OUT to result in unexpected_phase
; interrupts so that data overruns may be trapped.
;
; INPUTS : DSA - SCSI command
;
; CALLS : OK in data_transfer_start, not ok in other_out and other_in, ok in
; other_transfer
;
; MODIFIES : SCRATCH
;
; EXITS : if STATUS IN is detected, signifying command completion,
; the NCR jumps to command_complete. If MSG IN occurs, a
; CALL is made to msg_in. Otherwise, other_transfer runs in
; an infinite loop.
;
ENTRY data_transfer
data_transfer:
JUMP cmdout_cmdout, WHEN CMD
CALL msg_in, WHEN MSG_IN
INT int_err_unexpected_phase, WHEN MSG_OUT
JUMP do_dataout, WHEN DATA_OUT
JUMP do_datain, WHEN DATA_IN
JUMP command_complete, WHEN STATUS
JUMP data_transfer
ENTRY end_data_transfer
end_data_transfer:
;
; FIXME: On NCR53c700 and NCR53c700-66 chips, do_dataout/do_datain
; should be fixed up whenever the nexus changes so it can point to the
; correct routine for that command.
;
#if (CHIP != 700) && (CHIP != 70066)
; Nasty jump to dsa->dataout
do_dataout:
#if (CHIP == 710)
MOVE MEMORY 4, saved_dsa, addr_scratch
#else
CALL dsa_to_scratch
#endif
MOVE SCRATCH0 + dsa_dataout TO SCRATCH0
MOVE SCRATCH1 + 0 TO SCRATCH1 WITH CARRY
MOVE SCRATCH2 + 0 TO SCRATCH2 WITH CARRY
MOVE SCRATCH3 + 0 TO SCRATCH3 WITH CARRY
DMODE_NCR_TO_MEMORY
MOVE MEMORY 4, addr_scratch, dataout_to_jump + 4
DMODE_MEMORY_TO_MEMORY
dataout_to_jump:
MOVE MEMORY 4, 0, dataout_jump + 4
#if (CHIP == 710)
; Time to correct DSA following memory move
MOVE MEMORY 4, saved_dsa, addr_dsa
#endif
dataout_jump:
JUMP 0
; Nasty jump to dsa->dsain
do_datain:
#if (CHIP == 710)
MOVE MEMORY 4, saved_dsa, addr_scratch
#else
CALL dsa_to_scratch
#endif
MOVE SCRATCH0 + dsa_datain TO SCRATCH0
MOVE SCRATCH1 + 0 TO SCRATCH1 WITH CARRY
MOVE SCRATCH2 + 0 TO SCRATCH2 WITH CARRY
MOVE SCRATCH3 + 0 TO SCRATCH3 WITH CARRY
DMODE_NCR_TO_MEMORY
MOVE MEMORY 4, addr_scratch, datain_to_jump + 4
DMODE_MEMORY_TO_MEMORY
ENTRY datain_to_jump
datain_to_jump:
MOVE MEMORY 4, 0, datain_jump + 4
#if (CHIP == 710)
; Time to correct DSA following memory move
MOVE MEMORY 4, saved_dsa, addr_dsa
#endif
#ifdef DEBUG
INT int_debug_datain
#endif
datain_jump:
JUMP 0
#endif /* (CHIP != 700) && (CHIP != 70066) */
; Note that other_out and other_in loop until a non-data phase
; is discovered, so we only execute return statements when we
; can go on to the next data phase block move statement.
ENTRY other_out
other_out:
#if 0
INT 0x03ffdead
#endif
INT int_err_unexpected_phase, WHEN CMD
JUMP msg_in_restart, WHEN MSG_IN
INT int_err_unexpected_phase, WHEN MSG_OUT
INT int_err_unexpected_phase, WHEN DATA_IN
JUMP command_complete, WHEN STATUS
JUMP other_out, WHEN NOT DATA_OUT
#if (CHIP == 710)
; TEMP should be OK, as we got here from a call in the user dataout code.
#endif
RETURN
ENTRY other_in
other_in:
#if 0
INT 0x03ffdead
#endif
INT int_err_unexpected_phase, WHEN CMD
JUMP msg_in_restart, WHEN MSG_IN
INT int_err_unexpected_phase, WHEN MSG_OUT
INT int_err_unexpected_phase, WHEN DATA_OUT
JUMP command_complete, WHEN STATUS
JUMP other_in, WHEN NOT DATA_IN
#if (CHIP == 710)
; TEMP should be OK, as we got here from a call in the user datain code.
#endif
RETURN
ENTRY other_transfer
other_transfer:
INT int_err_unexpected_phase, WHEN CMD
CALL msg_in, WHEN MSG_IN
INT int_err_unexpected_phase, WHEN MSG_OUT
INT int_err_unexpected_phase, WHEN DATA_OUT
INT int_err_unexpected_phase, WHEN DATA_IN
JUMP command_complete, WHEN STATUS
JUMP other_transfer
;
; msg_in_restart
; msg_in
; munge_msg
;
; PURPOSE : process messages from a target. msg_in is called when the
; caller hasn't read the first byte of the message. munge_message
; is called when the caller has read the first byte of the message,
; and left it in SFBR. msg_in_restart is called when the caller
; hasn't read the first byte of the message, and wishes RETURN
; to transfer control back to the address of the conditional
; CALL instruction rather than to the instruction after it.
;
; Various int_* interrupts are generated when the host system
; needs to intervene, as is the case with SDTR, WDTR, and
; INITIATE RECOVERY messages.
;
; When the host system handles one of these interrupts,
; it can respond by reentering at reject_message,
; which rejects the message and returns control to
; the caller of msg_in or munge_msg, accept_message
; which clears ACK and returns control, or reply_message
; which sends the message pointed to by the DSA
; msgout_other table indirect field.
;
; DISCONNECT messages are handled by moving the command
; to the reconnect_dsa_queue.
#if (CHIP == 710)
; NOTE: DSA should be valid when we get here - we cannot save both it
; and TEMP in this routine.
#endif
;
; INPUTS : DSA - SCSI COMMAND, SFBR - first byte of message (munge_msg
; only)
;
; CALLS : NO. The TEMP register isn't backed up to allow nested calls.
;
; MODIFIES : SCRATCH, DSA on DISCONNECT
;
; EXITS : On receipt of SAVE DATA POINTER, RESTORE POINTERS,
; and normal return from message handlers running under
; Linux, control is returned to the caller. Receipt
; of DISCONNECT messages pass control to dsa_schedule.
;
ENTRY msg_in_restart
msg_in_restart:
; XXX - hackish
;
; Since it's easier to debug changes to the statically
; compiled code, rather than the dynamically generated
; stuff, such as
;
; MOVE x, y, WHEN data_phase
; CALL other_z, WHEN NOT data_phase
; MOVE x, y, WHEN data_phase
;
; I'd like to have certain routines (notably the message handler)
; restart on the conditional call rather than the next instruction.
;
; So, subtract 8 from the return address
MOVE TEMP0 + 0xf8 TO TEMP0
MOVE TEMP1 + 0xff TO TEMP1 WITH CARRY
MOVE TEMP2 + 0xff TO TEMP2 WITH CARRY
MOVE TEMP3 + 0xff TO TEMP3 WITH CARRY
ENTRY msg_in
msg_in:
MOVE 1, msg_buf, WHEN MSG_IN
munge_msg:
JUMP munge_extended, IF 0x01 ; EXTENDED MESSAGE
JUMP munge_2, IF 0x20, AND MASK 0xdf ; two byte message
;
; XXX - I've seen a handful of broken SCSI devices which fail to issue
; a SAVE POINTERS message before disconnecting in the middle of
; a transfer, assuming that the DATA POINTER will be implicitly
; restored.
;
; Historically, I've often done an implicit save when the DISCONNECT
; message is processed. We may want to consider having the option of
; doing that here.
;
JUMP munge_save_data_pointer, IF 0x02 ; SAVE DATA POINTER
JUMP munge_restore_pointers, IF 0x03 ; RESTORE POINTERS
JUMP munge_disconnect, IF 0x04 ; DISCONNECT
INT int_msg_1, IF 0x07 ; MESSAGE REJECT
INT int_msg_1, IF 0x0f ; INITIATE RECOVERY
#ifdef EVENTS
INT int_EVENT_SELECT_FAILED
#endif
JUMP reject_message
munge_2:
JUMP reject_message
;
; The SCSI standard allows targets to recover from transient
; error conditions by backing up the data pointer with a
; RESTORE POINTERS message.
;
; So, we must save and restore the _residual_ code as well as
; the current instruction pointer. Because of this messiness,
; it is simpler to put dynamic code in the dsa for this and to
; just do a simple jump down there.
;
munge_save_data_pointer:
#if (CHIP == 710)
; We have something in TEMP here, so first we must save that
MOVE TEMP0 TO SFBR
MOVE SFBR TO SCRATCH0
MOVE TEMP1 TO SFBR
MOVE SFBR TO SCRATCH1
MOVE TEMP2 TO SFBR
MOVE SFBR TO SCRATCH2
MOVE TEMP3 TO SFBR
MOVE SFBR TO SCRATCH3
MOVE MEMORY 4, addr_scratch, jump_temp + 4
; Now restore DSA
MOVE MEMORY 4, saved_dsa, addr_dsa
#endif
MOVE DSA0 + dsa_save_data_pointer TO SFBR
MOVE SFBR TO SCRATCH0
MOVE DSA1 + 0xff TO SFBR WITH CARRY
MOVE SFBR TO SCRATCH1
MOVE DSA2 + 0xff TO SFBR WITH CARRY
MOVE SFBR TO SCRATCH2
MOVE DSA3 + 0xff TO SFBR WITH CARRY
MOVE SFBR TO SCRATCH3
DMODE_NCR_TO_MEMORY
MOVE MEMORY 4, addr_scratch, jump_dsa_save + 4
DMODE_MEMORY_TO_MEMORY
jump_dsa_save:
JUMP 0
munge_restore_pointers:
#if (CHIP == 710)
; The code at dsa_restore_pointers will RETURN, but we don't care
; about TEMP here, as it will overwrite it anyway.
#endif
MOVE DSA0 + dsa_restore_pointers TO SFBR
MOVE SFBR TO SCRATCH0
MOVE DSA1 + 0xff TO SFBR WITH CARRY
MOVE SFBR TO SCRATCH1
MOVE DSA2 + 0xff TO SFBR WITH CARRY
MOVE SFBR TO SCRATCH2
MOVE DSA3 + 0xff TO SFBR WITH CARRY
MOVE SFBR TO SCRATCH3
DMODE_NCR_TO_MEMORY
MOVE MEMORY 4, addr_scratch, jump_dsa_restore + 4
DMODE_MEMORY_TO_MEMORY
jump_dsa_restore:
JUMP 0
munge_disconnect:
#ifdef DEBUG